Logic Seminar

Friday November 06, 2009

Organizer: Inessa Epstein

14:00-15:30 in MS 5233
Clint Conley
Limits Superior and Countably Chromatic Ideals
Abstract. We discuss how the machinery behind Miller's recent (classical) proof of the G_0 dichotomy can be modified to grant Komjath-Laczkovich-style limsup dichotomies.  In particular, this gives a classical proof of Gao-Jackson-Kieftenbeld's "sequential" generalization of Silver's theorem concerning the number of equivalence classes of a coanalytic equivalence relation.  Time permitting, we will also discuss obstacles preventing a similar "sequential" generalization of the G_0 dichotomy itself.